离子色谱法同时测定大气降水中7种阴离子

建立离子色谱法同时测定大气降水中F^-,Cl^-,NO2^-,Br-,NO3^-,SO4^2-和PO43^-7种阴离子的分析方法。选用IonPac■AS19型色谱柱(4 mm×250 mm),以KOH梯度淋洗,用抑制电导检测器进行测定。7种阴离子在各自的质量浓度范围内与色谱峰面积成良好的线性关系,相关系数均不小于0.997,方法检出限为0.002~0.004 mg/L。测定结果的相对标准偏差为0.80%~3.38%(n=6),样品加标回收率为75.0%~98.7%。该方法简便、快速,灵敏度高,适用于大气降水中F^-,Cl^-,NO2^-,Br^-,NO3^-,SO4^2-和PO43^-7种阴离子的同时测定。     

NaAc介质对离子色谱法测定微量阴离子的影响

离子色谱法自1975年问世以来发展很快，已在环境监测、电力、半导体工业、食品、石油化工、医疗卫生和生化等领域得到广泛应用，并有数十项获有关国家批准的标准方法。美国国家环保总局规定水中的无机离子F^-、Cl^-、Br^-、NO2^-、NO3^-、PO4^3-、SO4^2-可用离子色谱法检测。我国生活饮用水标准检测方法也考虑将离子色谱法作为国家标准方法加以应用，由于环境样品常伴随有机弱酸的出现，但未见NaAc介质中微量F^-、NO3^-、SO4^2-、CO3^2-、Cl^-等阴离子测定方法的报道。因此笔者探讨了NaAc介质中Ac^-对测定F^-、Cl^-、CO3^2-、NO3^-、SO4^2-等阴离子的干扰情况及消除干扰的方法。     

失效阴离子分离柱性能恢复试验

国产YSA8型阴离子分离柱，因失效无法分离F^-、Cl^-、NO3^-和SO4^2- 4种离子，用HCL法处理，并重新选择合适淋洗液浓度后，能成功地分离F^-、Cl^-、NO3^-和SO4^2-。用美国Dionex公司AS4A型柱和国产YSA8型柱对同一样品测定，分析结果相近，基本上满足实验要求。     

广州秋季灰霾和正常天气PM2.5中水溶性离子特征

为了探讨细粒子(PM2.5)在灰霾天气下水溶性离子的组分特征,2007年秋季在广州万顷沙连续一个月采集了大气PM2.5样品,分析了SO42-,NO3-,NH4+,Cl-,Na+,K+,Ca2+,C2O42-,F-,NO2-和HCOO-11种水溶性离子含量.结果显示,正常天气和灰霾天气PM2.5总水性离子质量浓度分别为3...     

离子色谱法测定AgNO3中的微量Cl-、NO2-和SO42-

用离子色谱法测定AgNO3溶液中的Cl^-、NO2^-和SO4^2-，以5.0mmol/L Na2CO3-5.0mmol/L NaHCO3混合溶液作淋洗液，采用离子交换法将AgNO3转换成KNO3，以除去Ag ^ 。讨论了NO3^-对Cl^-、NO2^-和SO4^2-测定的影响。AgNO3溶液中Cl^-、NO2^-和SO4^2-的回收率分别为93.3%、108%和94%。     

DX-80型离子色谱仪在地表水常见阴离子监测中的应用

介绍DX－80型离子色谱仪在监测地表水中F^-、Cl^-、NO3^-和SO4^2-的应用，用Chromeleon色谱软件绘制工作曲线，线性相关系数为0.9998-1.0000，回收率为99.24%-103.6%。     

IC5000型离子色谱仪在水环境监测中的应用

利用IC5000型离子色谱仪建立了水环境中F^-、Cl^-、NO3^-－N和SO4^2-的定量分析方法，相对标准偏差为0.54%-3.63%，回收率为97.2%-104.1%。对该仪器使用中常见的问题及解决方法作了论述。     

土壤中草甘膦的离子色谱法测定

采用新型抑制器和电导检测，在流速为1．5mL／min的碳酸钠和碳酸氢钠的混合淋洗液中，分离含F^-、Cl^-、NO3^-、SO4^2-和草甘膦等物质，取得理想的分离效果和较高的灵敏度；F^-、Cl^-、NO3^-、SO4^2-和草甘膦检出限分别为0.26、0.41、0．41、1．15、17．4μg／L(S／N=3)，具有良好的线性关系和重复性；对土壤样品进行测定，结果令人满意。     

离子色谱法测定水中的F-、Cl-、NO2--N、NO3--N、SO42-

应用DX－102型离子色谱仪测定水中的F^-、Cl^-、NO2^-－N、NO3^-－N及SO4^2-，淋洗液为1.42mmol/L NaHCO3-1.50mmol/L Na2CO3溶液，淋洗液流速为1.8mL/min，进样量为25μL。5种离子在上述实验条件下分离良好，定量测定的线性相关系数均在0.9995以上。     

北京水环境中主要阴离子污染物的监测

针对北京水环境的特点，选定了适宜的色谱条件，用离子色谱法对水环境中常见的阴离子污染物F^-、Cl^-、NO3^-－N和SO4^2-，进行了定量监测，并确定了主要的定量分析掺数。该方法用于实际样品的分析，取得了满意的结果。     

AM1, PM3, and PM5 calculations of the absorption maxima of basic organic dyes

The absorption maxima, λ_max, of various organic dyes such as indigo, azobenzene, phenylamine, hydrazone, anthraquinone, naphthoquinone, and malachite green were calculated using the AM1, PM3, and PM5 semiempirical molecular orbital theories with the configuration interaction singles (CIS) and random phase approximation (RPA) approaches. The calculated λ_max were then compared with the values obtained by CNDO/S, INDO/S, ab initio CIS, and time-dependent density functional theory (TD-DFT). We found that the λ_max values calculated by AM1, PM3, and PM5 were in good correlation with the observed λ_max values. When B3LYP/cc-pVDZ optimized geometries were used, the square of the correlation coefficients between the calculated and observed λ_max, , at the AM1-RPA, PM3-RPA, and PM5-RPA levels were 0.891, 0.897, and 0.927, respectively. In particular, at PM5-RPA//B3LYP/cc-pVDZ was the largest among those obtained from all the other calculations including TD/B3LYP/cc-pVDZ//B3LYP/cc-pVDZ . Accordingly, the standard deviation of the difference between observed and calculated λ_max by the linear regression function at PM5-RPA//B3LYP/cc-pVDZ was the smallest. It was therefore concluded that this method was the most promising for the prediction of λ_max of various dyes among the computational methods studied here. When AM1 optimized geometries were used, at the AM1-RPA, PM3-RPA, and PM5-RPA levels were 0.822, 0.841, and 0.901, respectively, and they were also comparable to that at TD/B3LYP/cc-pVDZ//B3LYP/cc-pVDZ. Therefore, although some calibration efforts may be needed for AM1 geometries, PM5-RPA(CIS)//AM1 may be a second candidate available for the prediction of the absorption maxima of dyes, especially in the case of emphasizing computational cost.     

离子色谱-电感耦合等离子体质谱联用测定大气颗粒物PM2.5和PM10中的六价铬

建立了大气颗粒物PM_2.5、PM₁₀中六价铬（Cr（Ⅵ））的离子色谱-电感耦合等离子体质谱（IC-ICP-MS）检测方法。采用碳酸氢钠（NaHCO₃）溶液超声提取大气颗粒物样品中的Cr（Ⅵ）,并使用含有0.22 g/L 乙二胺四乙酸二钠盐（Na₂EDTA）的75 mmol/L硝酸铵溶液（pH 7.0）淋洗液通过离子色谱柱（AG7,50 mm×4 mm）分离出样品中的Cr（Ⅵ）,电感耦合等离子体质谱测定。标准溶液中Cr（Ⅵ）的质量浓度在0.05~5 μg/L范围内呈良好的线性关系,相关系数达0.9999,标准溶液测定的精密度为1.0%~4.0%,标准样品测定的相对误差为3.3%;纤维素滤膜适用于Cr（Ⅵ）的采样,将纤维素滤膜碱化后,Cr（Ⅵ）的回收率从75%增加到102%;样品在20 mmol/L碳酸氢钠溶液中超声30 min后上机测试,提取完全且回收率稳定;当采样体积为20 m³,方法的检出限为0.0004 ng/m³;采集并测定了PM_2.5及PM₁₀实际样品,样品的加标回收率为91.6%~102%,精密度为1.7%~7.6%。该方法高效、稳定、灵敏,适用于大气颗粒物中六价铬的测定。     

Comparative parametric method 5 (PM5) study of trans-stilbene

In this work we report a comparative Austin method 1 (AM1), parametric method 3 (PM3), and parametric method 5 (PM5) studies for trans-stilbene in its ground, excited (singlet and triplet), and ionic (positive and negative polarons and bipolarons) states. We evaluated the accuracy of the recently developed PM5 method. PM5 and AM1 predict a non-planar ground and singlet states for trans-stilbene, while PM3 predicts planar ones, which is in agreement with the available experimental data. In general the PM3 and PM5 bond lengths are superior to AM1 while AM1 bond angles are superior to PM3 and PM5 when compared with available experimental data. The PM5 underestimates the cis–trans isomerization energy and and it is not a quite reliable method for the calculation of relative IP values. The presumed PM5 superior performance against AM1 and PM3 was not observed for the stilbene structures.     

电感耦合等离子体质谱法测定PM2.5中的重金属元素

采集环境空气细颗粒物(PM2.5)样品,建立了电感耦合等离子体质谱法(ICP-MS)同时测定PM2.5中10种重金属元素的方法。样品经5%HNO_3超声浸提,过滤后,用ICP-MS测定。结果表明:10种重金属元素的检出限在0.030μg/L~0.13μg/L之间;线性关系良好,精密度为0.82%~4.3%,回收率为80.1%~113.0%。该方法快速、准确,可用于PM2.5中重金属元素的测定。     

Pollution characteristics of ambient PM2.5-bound PAHs and NPAHs in a typical winter time period in Taiyuan

The pollution characteristics of ambient fine particulate matter（PM2.5） containing polycyclic aromatic hydrocarbons（PAHs） and nitrated PAHs（NPAHs） in samples collected during a typical winter time period in Taiyuan of China were investigated.The obtained results revealed that the mean mass concentrations of PM2.5,SPAHs（sum of 16 PAHs） and SNPAHs（sum of 3 NPAHs） on PM2.5were161.4 mg/m3,119.8 ng/m3and 0.446 ng/m3,respectively.Diagnostic ratios of PAHs and NPAHs implied that coal consumption might be the main source of the PM2.5pollution.The measured PM2.5mass concentrations,BaP equivalent toxicity（28.632 ng/m3） and individual carcinogenicity index（3.14 10 5） were much higher than those of the recommended safety standards.     

微波消解–原子荧光法同时测定PM2.5中砷、汞含量

采用微波消解–原子荧光法测定PM2.5中砷、汞含量。实验结果表明,当还原剂硼氢化钾的质量分数为2%、溶液介质酸度为4%(体积分数)盐酸时,同时测定砷、汞可获得最佳的荧光值。砷、汞测定的检出限分别为0.027,0.006μg/L,空白滤膜的加标回收率分别为95.3%~101.7%,96.0%~106.0%,样品的加标回收率分别为95.0%~103.5%,93.3%~110.0%。该法检出限低,准确度高,适用于环境空气PM2.5中砷、汞含量的测定。     

Chemical characterization of PM10 fractions of urban aerosol

The goal of this investigation was to give an overview about the trace metal and total organic/inorganic carbon (TOC/TIC), water-soluble carbon (WSOC) and polyaromatic hydrocarbons (PAH) concentrations in the PM10 aerosol fraction in Budapest and to monitor monthly changes during the sampling period, whether there is a tendency in the seasonal change of the concentrations. The sampling took place in Budapest, Hungary between September 2004 and August 2007 in an area with high traffic density. For the sampling, a high-volume aerosol sampler equipped with a PM10 head was used. The samples were taken onto quartz fiber filters. Each month, one sample was collected. Sampling time was 96 h, the air intake was 30 m³/h, resulting in 2880 m³ sampled air volume.To measure the metal concentrations two types of sample preparation were used: microwave assisted aqua regia extraction and water extraction by sonication. In both cases, the solutions were analyzed by using a sector field inductively coupled plasma mass spectrometer (SF-ICP-MS). The following 23 elements were investigated: V, Cd, Zn, Cu, Ni, Sb, Sn, Cr, Pt, Pb, Te, Tl, U, Mn, Fe, Co, Ga, Rb, Sr, Mo, Ag, Bi, Li. Comparing the data obtained from the aqua regia extraction to some other cities, the measured trace elements were found in moderate concentration. In the water extract, a significant part of zinc and thallium was found. During the sampling period, no proof of seasonal change in trace element concentrations was found. Trace metal and total organic/inorganic carbon concentrations in Budapest were similar to the concentration data measured in other cities with exception of Mn, Ga, Rb, Cd which are present in higher concentration in Budapest. The TOC content in the PM10 fraction amounted to 30-50%, and its value was the highest during the winter period due to the heating.The yearly average concentration of polyaromatic hydrocarbons was almost constant over the investigated period, but its seasonal change is more than one order of magnitude.     

苯并噻二嗪F,Cl,Br和I取代衍生物电子性质的PM3研究

采用半经验PM3方法对1，2，4-苯并噻二嗪-1，1-二氧类化合物的4种衍生物进行了量子化学计算，从几何构型、电子结构、前线分子轨道等几方面探讨了取代后体系电子性质的规律性变化，，为药物合成提供理论基础和实验指导．     

校园室内外大气PM2.5中的含碳气溶胶及室内源特征

分夏、冬季采集南昌大学前湖校区室外和3个不同室内环境中的PM2.5,测定有机碳(OC)和元素碳(EC),并分析室内、外碳气溶胶质量浓度及其分布特征;利用OC-EC关系式半定量分析室内排放源;结合室内、外二次有机碳(SOC)和SOC/OC的分布进一步讨论不同室内排放源的特征及对SOC的影响;对4个采样点的8个碳组分丰度特征比较分析,结果表明复印/打印机对室内OC的贡献高,8个碳组分的丰度分布特征与其它排放源具有较明显的差异。     

广州市夏、冬季室内外PM2.5中元素组分的特征与来源

通过采集广州市9个居民住宅室内、外的PM2.5样品,测定分析PM2.5中18个元素组分的质量浓度,分析讨论其污染、分布特征并解析其污染来源。经过比较得知,广州市PM2.5中元素污染较严重;不同类型住宅PM2.5中元素浓度存在空间分布特征;大部分元素浓度具有夏季比冬季低的变化特征;室内与室外元素浓度比值介于0.4974～2.0497之间;元素浓度的室内、室外相关拟合结果说明冬季室内空气受室外空气影响比夏季时情况更明显;基于富集因子分析,Se、As、S、Pb、Br、Zn和Cl元素高度富集;Ni、V、Cu元素中等富集,主要来自人为源,而Cr、Sr、K、Mn、Ca和Ti元素不富集,主要来自自然源。